The present invention relates to a vehicle door latch device having a childproof lock mechanism.
A conventional vehicle door latch device comprises an inside operating lever operated by an inside handle in the interior of the vehicle; a contact lever for transmitting motion of the inside operating lever to an engagement unit for holding a door closed; and a childproof lock lever that can change between a locking state for disconnecting the inside operating lever from the contact lever and an unlocking state for connecting them, the three levers being overlapped and mounted to the casing, as disclosed in JP2009-235805A.
However, in the door latch device, when the levers are coupled to the casing, the inside operating lever, contact lever and childproof lock lever are freely movable from each other. Thus, when the casing is closed by a cover after the levers are coupled to the casing, each of the levers can deviate from a normal mounting position and the deviated lever will obstruct mounting of the cover to the casing, thereby decreasing assembling efficiency.